Typewriter carriage decelerator



y 969 c. P. ANDERSON 3,444,976

TYPEWRITER GARRI AGE DECELERATOR Filed Oct. 10, 1967 INVENTOR.

CARL F. ANDERSON WLAI AGENT United States Patent 3,444,976 TYPEWRITERCARRIAGE DECELERATOR Carl P. Anderson, Homer, N.Y., assignor to SCMCorporation, organized under the laws of New York Filed Oct. 10, 1967,Ser. No. 674,308 Int. Cl. B413 19/02, 29/10, 19/04 US. Cl. 197-64 5Claims ABSTRACT OF DISCLOSURE A carriage decelerator for typewritershaving a mechanism for accelerating a speed responsive centrifugalgovernor. The mechanism includes a counterstop slide operable by acarriage supported margin stop, a lever pivotally mounted on the slide,a sector gear connected to the lever and to the governor and a rigidplate having a curved surface engageable by the lever in a manner tocause the lever to pivot about its axis at an accelerating rate whichaccelerates the governor for decelerating the carriage.

Background of the invention The present invention includes a lever whichinterconnects the counterstop slide and the governor driving sectorgear. When the carriage margin stop contacts and moves the slide towardthe end of the carriage return run, the lever, which is pivotallymounted on the slide, is moved against a rigid curved surface forcausing an accelerated pivoting of the lever. This motion is imparted tothe governor by way of the sector gear and the braking force is impartedback through the mechanism to decelerate the carriage.

Description of the drawing FIGURE 1 is a perspective view illustratingthe mechanism in its rest position and the carriage left margin stop ina position just prior to contacting the counterstop slide; and

FIGURE 2 is a front elevational view of the lever and the curved surfaceof the rigid plate and illustrating four different positions of thelever during a deceleration operation.

Description of the preferred embodiment Referring to the drawing andparticularly to FIGURE 1, the counterstop slide is mounted on a rigidframe shaft 12 for movement along the shaft. The slide 10 is limited forleftward movement by a left shaft support bracket 14 while it is limitedfor rightward movement by a rubber abutment 16. The slide 10 is normallbiased against the left limit 14 by a tension spring 18 and has a lowerextension 20 with the lever 22 pivotally mounted thereon by way of astud 24. The sector gear 26 is pivotally mounted on a frame bracket 28by a stud 30 and is connected to the lever 22 by way of a link 32 in amanner whereby a counterclockwise motion of the lever 22 would cause aclockwise motion of the sector gear 26.

3,444,976 Patented May 20, 1969 "ice The teeth 34 of sector gear 26 meshwith teeth of a governor driving pinion 36 which is rigidly mounted onthe upper end of a governor shaft 38 of a governor 39. The shaft 38 ispivotally mounted within the governor housing 40 and provides a meansfor-rigidly supporting a pair of centrifugal dog retainer plates 42. Theretainer plates 42 are rigidly mounted to each other by a pair of pins44 and straddle a pair of centrifugal dogs 46 which pivot about the pins44 upon rotation of the governor shaft 38. Each dog 46 has a frictionpad 50 carried thereby that contacts the side wall 48 of the housing 40to resist the rotation of shaft 38 which, in turn, resists the motion ofthe remaining mechanism for decelerating the carriage. The governor 39is rigidly mounted on a frame member 52 by screws 53 and the governor 39is responsive in offering more frictional resistance to the mechanismthe faster the governor 39 is rotated.

A plate 54 which is rigidly mounted to the rear frame 56 by screws 58has a curved surface portion 60 against which the upper portion of thelever 22 acts. The lever 22 is normally biased clockwise about its pivotstud 24 through link 32 and sector gear 26 by a tension spring 62 so theupper end of the lever 22 is in contact with surface 60 of the plate 54.

When the carriage is returned, the carriage margin stop 64 contacts theslide upper extension 66 near the end of the carriage run and drives theslide 10 to the right and the plate 54 causes the lever 22 to pivotcounterclockwise as the pivot center of the lever 22 moves in asubstantially horizontal line. As the lever 22 is pivoted, the sectorgear 26 is moved in a clockwise direction and the governor shaft 38 isthereby rotated in a counterclockwise direction whereupon thecentrifugal dog friction pads 50 are pressed against the governorhousing 40 to affect a braking force on the carriage.

The deceleration of the carriage is accomplished by pivoting the lever22 at an accelerated rate. More specifically, referring to FIGURE 2, thecurved shape of the plate surface 60 provides a variable fulcrum for thelever 22 as stud 24 moves to the right. By varying the fulcrum abovestud 24 as the lever 22 moves to the right, the lower portion of thelever 22, which is operatively connected to the governor shaft 38, isactuated with an increased linear velocity. This is illustrateddiagrammatically by the different lever lower portion linear distances68 and 70. The distance 70 for a given movement of stud 24 at the end ofthe lever working movement is greater than the distance 68 for the samestud 24 movement at the beginning of the lever working movement. Thisaccelerated linear velocity of the link 32 effects an acceleratedrotation of the governor shaft 38 which acts upon the carriage throughthe mechanism and decelerates the carriage until the slide 10 is finallyarrested by the rubber abutment 16.

It can now be seen that the mechanism just described provides atypewriter carriage decelerating means for reducing noise and shock atthe end of a carriage return run and is of a simple and economicalconstruction.

What is claimed and desired to be secured by Letters Patent is:

1. In a typewriter having a power driven carriage mounted for movementacross a printing position and a device for decelerating the carriage asit travels through a predetermined distance of power driven movementcomprising:

(a) a member (10) mounted for sliding movement in response to movementof the carriage when the carriage travels through said predetermineddistance;

(b) a lever (22) operable by the movement of said slideable member;

(c) an energy absorber (39);

(d) means (26, 32) interconnecting said energy ab- 4 sorber (39) andsaid lever (22); and

(e) a rigid plate (54) having a curved surface (60) engageable by saidlever for pivoting said lever at an accelerated rate as said slideablemember is moved by the carriage to actuate said energy absorber therebydecelerating the carriage during said predetermined distance.

2. A typewriter as defined in claim 1 wherein said en- 4 center (24) ofsaid lever (22)-moves in a substantially horizontal line, saidinterconnecting means (26, 32) being "connected to said lever on oneside of said pivot center and said rigid plate (54) acts on said leveron the opposite side of said pivot center. v

References Cited v UNITED STATES PATENTS:

2,829,754 4/1958 Norcross; 2,854,124 9/1958 Dodge et a1. 2,926,7693/1960 Toeppen. 2,958,409 11/1960 Dodge et al.

' ERNESTT. wRiGHT, 111., Primary amt-"6;.

US. Cl. X.R.

